In recent years, there has been an increasing need for wireless communication in which the communication area is purposely limited (area limited wireless communication). For example, an electric field communication system disclosed in Patent Document 1 is one means for implementing the area limited wireless communication.
Meanwhile, low-frequency (approximately 10 MHz) magnetic fields have such a characteristic that they interact with human bodies and surrounding environments significantly less than electric fields do. For example, a loop antenna disclosed in Patent Document 2 generates a magnetic field in a limited space.